Barcelona striker David Villa could be out for at least six months after he was stretchered off with what the club said was a fractured left tibia during their 4-0 Club World Cup semi-final win over Qatar's Al Sadd Thursday.

A weakened Barca outclassed the Asian champions to set up a final clash with Santos, but the result was overshadowed by the injury to the Spain international, recently linked with a move away from the Camp Nou.

"He broke his bone so he will be returning to Barcelona as soon as possible," said a sombre Pep Guardiola, Barcelona's coach.

"It will take some time to return to the team. I'm very sad to say this. It's very unfortunate.

"I was talking to the other players in the changing room and saying that to recover from a broken bone takes time."

Guardiola added that Javier Mascherano and Alexis Sanchez, who replaced Villa on 39 minutes, also picked up injuries, but was unable to say how serious they were.

And he added of the 30-year-old Villa: "He's going back to Spain to have an operation. Missing him is a blow to our team. We are very sad and hope that he will recover as quickly as possible."

Guardiola left Xavi, Dani Alves, Cesc Fabregas and Gerard Pique on the bench, but it hardly mattered as the Qataris, the Asian champions, were torn apart.

As anticipated, it was all Barcelona from the off at a packed International Stadium in Yokohama, near Tokyo, in a game that felt more like an exhibition match than a competitive fixture for the 66,298 fans.

Barca had a mammoth 70 percent of the possession in the first 15 minutes, pinging the ball around as Al Sadd chased shadows under the floodlights in a hopelessly one-sided contest. It was only a matter of time.

The only surprise was that it took the Catalans so long to register their first real shot on goal, with Mohamed Saqr in the Qataris' goal saving smartly from Villa just after 15 minutes.

Guardiola threw his hands up at one stage when one move broke down, but on 25 minutes the Spanish side went ahead, and it had nothing to do with their class and everything to do with some hugely comical defending.

A cross from the left fell tamely to former English Premier League defender Nadir Belhadj, who controlled the ball, which ran loose to Saqr.

But Saqr, who like the Algerian Belhadj was one of the heroes of Al Sadd's unlikely run to the Asian crown, hesitated over whether he should pick it up, and as he thought about it the Brazilian Adriano nipped in to prod home.

Villa was replaced by Sanchez five minutes before half-time in what did not at the time look a serious injury.

Al Sadd could not get out of their own half and it was no surprise when the Spanish champions went 2-0 up, Adriano rifling the ball low and hard under Saqr, who again ought to have done better.

Seydou Keita grabbed the third after he was set up by Lionel Messi, who had a quiet night by his exceptionally high standards, as the news filtered through on Barcelona's website of Villa's injury.